Urban landscape lighting such as road lighting, street lighting, square lighting and so on is commonplace in many urban areas to provide illumination of such areas, which for instance is important for safety and security reasons. Many types of luminaires are used for urban landscape lighting, such as for instance post-top lighting, column lighting, bollard lighting and so on.
The functional lighting provided by such luminaries typically has to meet specific regulations in order to ensure that appropriate lighting levels are provided in a safe manner, e.g. by ensuring that glare levels produced by the luminaire are kept below defined thresholds.
Consequently, the design of such luminaires must be suitable to meet the aforementioned specific regulations. At the same time, because such luminaires are placed in urban environments, the appearance of such luminaires is important, for instance because the luminaire preferably has to blend into the environment in which it is placed. In other words, the luminaire preferably should be decorative whilst at the same time providing the required functional lighting in order to ensure that the luminaire is considered a welcome addition to the urban environment in which it is placed.
It has been recognized that the appearance of the luminaire in an urban landscape can be controlled not only by the appearance of the luminaire itself but also by shaping the luminous output of the luminaire. It is for instance is known to adjust the lighting pattern produced by a luminaire upon detection of a person in the vicinity of the luminaire. However, such dynamic variations of the lighting pattern may be beneficial for functional reasons but may not be considered aesthetically pleasing. In addition, the cost of such luminaires is significantly increased due to the requirement of motion detection sensors or the like and appropriate controllers responsive to such sensors that control the luminous output of the luminaire.
It is known per se to provide a lighting fixture that can create an aesthetically pleasing effect such as a kaleidoscopic effect. For instance, U.S. Pat. No. 5,711,598 A discloses a lamp device that includes a light emitting unit for emitting a light beam, a light filtering unit, first and second focusing lenses, and a total internal reflection unit. The light filtering unit has a rotatable glass-holding frame and a pair of flat glasses which are fixed opposedly to the glass-holding frame. A space is formed between the flat glasses to receive damping fluid in which a plurality of colored glass fragments are dispersed. The light filtering unit is positioned adjacent the light emitting unit so that the light beam from the light emitting unit can pass through the flat glasses and the colored glass fragments. The first and second focusing lenses are spaced opposedly from one another. The first focusing lens is positioned adjacent the light filtering unit. The total internal reflection unit is mounted between the first and second focusing lenses so that the light beam from the light filtering unit can be emitted through the first focusing lens, reflected by the total internal reflection unit, and emitted from the second focusing lens, thereby producing a kaleidoscopic light output.
However, such an arrangement is relatively complex and not particularly suitable in an urban lighting environment, for instance if a luminous output may have to be generated in a particular direction to meet functional lighting requirements.
EP2273185A1 discloses a light element with a light diverter which has a elongate carrier element, which is arranged along its peripheral around a longitudinal axis for supporting circuit carriers for light emitting diodes. The elongate carrier element has surface sections along its peripheral around the longitudinal axis. The light diverter has a plurality of segments. However, the light diverter is directly mounted to the elongate carrier element.